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Table 1 Substrate scope of Mannich bases synthesis

From: Single-step synthesis of a new series of meso di-Mannich bases from the cyclic aminal (2S,7R,11S,16R)-1,8,10,17-tetraazapentacyclo[8.8.1.1.8,170.2,7011,16]icosane and p-substituted phenols

Entry

Compound

R

Product

m.p. (°C)

[ α ] D 20

c = 0.6, CH2Cl2

Yield (%)

1

7a

F

8a

168-169

+5.2

20

2

7b

Cl

8b

189-190

+5.7

34

3

7c

Br

8c

183-184

+6.0

41

4

7d

I

8d

175-177

+7.1

20

5

7e

COOMe

8e

128-130

+6.3

17

6

7f

COOEt

8f

151-153

+6.8

19

7

7 g

COOPr

8 g

118-119

+5.5

18

8

7 h

COOBu

8 h

127-129

+4.9

19

9

7i

H

8i

146-148

+6.8

20

10

7j

Me

8j

162-163

+7.2

46

11

7 k

t-Bu

8 k

141-143

+6.3

49

12

7 l

OMe

8 l

132-134

+5.9

45

  1. Table 1 shows melting points and yield for each new compound, indicating the p-substituent in aromatic rings in both phenols and compounds 8a-l.